Drugstore chain Walgreens will stop selling tobacco products to customers under 21, the company announced today.

The decision came weeks after the Food and Drug Administration accused the company of repeatedly selling tobacco products to minors — and amid similar moves by competitors and lawmakers around the country to curb teenage vaping.

About a dozen states and hundreds of U.S. cities have already raised the minimum age to buy tobacco to 21. Last week, Sen. Mitch McConnell, R-Ky., the majority leader, said he would introduce a bill in May to raise the minimum age nationwide.

Rite Aid announced this month that it would stop selling all e-cigarettes and vaping products, citing concern over tobacco use among minors. (It will continue to sell regular tobacco products in areas where it is legal.) CVS stopped selling tobacco products in 2014.

Some cities, including San Francisco, Boston and New York, have also passed laws barring pharmacies from selling tobacco products.

What was Walgreens accused of?

Walgreens — one of the largest drugstore chains in the United States, with nearly 10,000 stores — had been subject to undercover inspections and “racked up almost 1,800 violations” related to the sale of tobacco products to minors, the FDA said last month.

Dr. Scott Gottlieb, who recently resigned as the agency’s commissioner, had made regulation of e-cigarettes and teenage vaping a priority of his tenure. He said that Walgreens was the top violator among the pharmacies the agency had inspected. The agency asked top executives from the chain to meet with officials to discuss the findings.

In a statement today, Walgreens said the new policy would go into effect in September. The company said that it supported laws to restrict tobacco sales to those 21 and over, had instituted a “Card All” policy at its stores, and would focus on promoting products that help people quit smoking.

Why the focus on teenagers?

Vaping’s popularity has exploded in recent years as manufacturers marketed the devices as a less-harmful alternative to cigarettes, or a way to help smokers quit. But vaping attracted other users: teenagers, who can easily become hooked on nicotine, however it is delivered.

Health officials say the habits formed during adolescence can persist for decades, and there is concern that vaping could lead to smoking cigarettes.

According to the 2017 National Survey on Drug Use and Health, almost all adult smokers begin smoking before they turn 21.

Additionally, adolescents and young adults are more susceptible to the effects of nicotine because their brains are still developing.

Marina Picciotto, a neuroscientist at Yale who is the former president of the Society for Research on Nicotine and Tobacco, said the brain’s prefrontal cortex, which controls judgment and impulse, is still maturing during the teenage years.

“When you flood it with nicotine, you are interrupting development,” Picciotto said.

States join in the ‘Tobacco 21’ movement

This month, Delaware became the 12th state to raise the legal age to purchase tobacco products to 21, according to the Campaign for Tobacco-Free Kids, an advocacy organization.

Arkansas, California, Hawaii, Illinois, Maine, Massachusetts, New Jersey, Oregon, Utah, Washington and Virginia, and at least 450 metro areas, including New York, Chicago, San Antonio, Boston, Cleveland, Minneapolis and Washington, D.C., have also made it illegal for those under 21 to purchase tobacco products.

Two states — New York and Maryland — have bills pending.

… But read the fine print

Tobacco and vaping companies have supported the push to restrict sales to youths, partly in response to accusations that they marketed their products to that same demographic. Altria, Juul and R.J. Reynolds Tobacco Co. all have said they support raising the minimum age.

At the same time, the companies have sought provisions that limit the regulation of tobacco products. For example, the companies fought back against efforts to limit flavored tobacco products, which are popular with teenagers, said Matthew L. Myers, president of the Campaign for Tobacco-Free Kids.

Some proposals could also make enforcement difficult, or penalize young people for buying tobacco products, rather than the stores that sold them.

Federal lawmakers are also making a push

McConnell, a longtime ally of the tobacco industry, said his proposed bill, which would restrict sales of both tobacco and e-cigarettes, was inspired by the rise in vaping among teenagers. He has yet to release details on the plan.

Two related measures have also been introduced in the House.

This month, Rep. Robert B. Aderholt, R- Ala., introduced the Stopping Consumption of Tobacco by Teens Act, to raise the minimum age to buy tobacco products to 21 and require more age verification for the online sale of vaping products.

The bill’s acronym, Scott, pays homage to Gottlieb. The Campaign for Tobacco-Free Kids has raised concerns about aspects of it.

A provision in the bill could classify a heated tobacco product being developed by Philip Morris International as a vapor product rather than a cigarette, thereby skirting stronger regulations.

“Tobacco companies must not be allowed to use this legislation as a Trojan horse for special-interest provisions that harm kids and public health,” Myers said in a statement.

His organization strongly supports a bill introduced last week by Reps. Frank Pallone Jr., D-N.J., and Donna Shalala, D-Fla., called the Reversing the Youth Tobacco Epidemic Act of 2019.

The bill would raise the minimum age to buy tobacco products, restrict the sale of flavored tobacco products and order the FDA to speed up work on other measures, including putting graphic health warnings on cigarette packages.